Coffee mill



Dec. Z7, 1938. D. A. MEEKER 2,141,310

COFFEE MILL Filed Fb. 13, 1935 3 Sheets-Sheet 2 M /af l' I 5, ,el As" I/al Z2 f. I /6' /s ZZ 6 /ez iii x22 1' Snnmtor Cttornegs Dec, 27, 1938.

D. A. 4MEEKER COFFEE MILL 3 Sheets-Sheet 3 Filed Feb 13, 1935 W25mn-emot attorneys Patented Dec. 27, 1938 d A-.Meeker; Troy, Ohimassgnn'r i Manufacturing Company,-4 'I' QiineI3A-v3 ofFig."2,fFig,Bishowinglthejparts infthe shown a base l upon which' ismounted a housthe,

milk.,

Fig; 'z 'islam elevatinal view `with parts `breken a double-ended mill;and

Fig. 8is a detail view on the line 8-1-8of-Fig. 7. f y l s structionshown vwhich'-inciudesi-ftheYlwiperslfor A wings 46 which help to 'feed'the y"ground"cieekintcfthe passage containing the Worm conveyorAinember 4l, 4the discharge end of Whichvis provided Referring tothe.'drawingswhichfshow a preferred`embodiment of the invention, thereis ing ,H for enclosing the operative partis of the mill. The housingenclose's a. suitable motor 12,

and a coffee receiving hopperrlil extends above' the housing forreceivingthecoieein bean form.

The hopper leads into the grinding means, and is controlled by means ofa suitablegate valve I5 whichlis mountedupon a shaft i6 journalled inthe frame portion IVIof the machine. A suitable handle i8 isprovided'rfor theoperation` of the shaft. A spring pressed fdetent I9cooperatesV attached to the =shaft' to yieidingly retain the f machineand Afitting within a suitablewrecessSZ Vformedin a'framernember53fattached to-"Ithe to' whichfthere is attached'an armv22ope`rative1y with spaced recesses in a. cylindrical' section 20 handleI8 in either' open or closed position. l

An inward extension is provided upon shaft i6 connected to alink"23flThe link` 23 has operative connection with the motor switch`24,confveniently located-'within the housing to provideAi'nf'ainrr'migeinem offtneirtary thereof and"y likewise haft-ass 'rfandto e conandlchaff. This is eifectedlby'meansfo withfeeding ribs of4greater pitch, the'coifee issuing therefrom` 'passingr downwardly Iintofthe 45 Means are provided for selecting the gradef'of 50 fineness towhifchfthe' coffee is to be ground. This means comprises the `hand wheelformed with a conical portion 5lfanda cylindrical Vfia'nge portionvfila,v extending toward the face of the 4voperation with a lfixed index,shown as arrows,

sponding index points on the cooperating nonmovable frame which permitsof ready reading of the burr setting by the clerk on one side of themachine and the customer on the other; the indications naturally being,insuch case, so arranged as to be readily read from the oppositepositions, as desired; the indications on the ro-rv tary member beingshown as indicating letters 'corresponding to the setting of the gradeselector mechanism. The hand wheel has a centrally located aperturethrough which there extends'a screw head 54 formed integrally with adisk 55 l which disk lis attached to a sleeve member 56 by means of aplurality of screws 51. The sleeve is provided with internal screwthreads 58 andis rotatably `mounted within the hollow projecting flangeof the stationary frame 53 with interposed bearing members 59 so thatthe sleeve 56 is freely rotatably mounted but is. held against axialmovement.

The sleeve 56 engages with a threaded shaft 60 which is provided with anon-circular end portion 6 1 which extends through .a cooperativelyformed non-circular recess in the frame member 53, thereby providing foraxial movement of the shaft BIJ whilerpreventing. rotational movementthereof. A suitable contact or thrustmember `62 is attached to the endof shaft B0 for engagement with the cup shaped member 36 which enclosesthe end of the shaft 35 and the surroundl ing hub of the burr 3,3,whereby controlled axial single hand movementthat is, within an anuguiar range of 180. Also, this -is of advantage where two sets ofindications are desired to be used, as above described.

From the above it will be clear that when the hand wheel 50 is rotated,sleeve 56 is likewise rotated and is held in fixed axial position bymeans of the bearing members 59. Rotation of sleeve 56 produces axialmovement of non-rotating shaft 60, toward or away from the movable burr33 to provide for moving such burr closer to or farther from thestationary burr 32 and thereby to control the ilneness of the grind.

A locking disk 65 is seated upon the sleeve 56 and is adapted to engage,and frictionally lock with, aY shoulder E6 formed thereon and to bedrawn up against such shoulder by means of a plurality of locking screws61. When these screws are tightened, sleeve 56 is retained in apredetermined relationship with the hand wheel 50, but upon theloosening of the locking screws 61, the sleeve may be adjusted withrespect to the hand wheel 50 by means of the screw head 54 to therebyproperly adjust the position of the burr with respect to theindications.

Means are provided for normally tending to move the grade selector meansin such direction as to adjust the burrs to their largest spacing, or toa non-grinding position. This means comprises an annually arrangedspiral spring 10 slldably held, within a groove 1I, in the conicalportion 5| of the hand wheel. One end of the spring 'abuts against a pin13 fixed in the frame 53, and

the other end of the spring is engaged by a pin 12 carried by the handwheel. Pin 12 engages with the endA ofthe spring and upon turning of thehand wheel causes compression of the spring sufilcient to return thegrade selector means to its olf or non-grinding position when the hand 4wheel is released. The spring is preferably preloaded, being of suchlength as to be under compression when the burrs are in the non-grindingposition, i. e., off position of the hand wheel indications; andthe pins12-13 are located out of line, so that as the spring expands to this offposition each pin 12-13 will control the other. end of the spring whichthus acts as its own energy absorber.

Means are provided for requiring an operation of the grade selectormeans away from the ofi position to a grinding'position before the millcan be started. Since this preliminary operation of the grade selectorto a grinding position is required each time the mill is operated, thereis more assurance that the operator will adjust theV mill in accordancewith the wishes of each individual customer. `This means comprises aninterlock member 15 pivotally mounted upon pin 16 attached to the frame53 and having an extended end portion 11 adapted to ride upon theoutside surface of the flange portion 5Ia of the hand wheel toward whichit is urged by spring 18. The disk 19 attached to and rotatable withshaft 16 and the handle I8 which controls the grinding operation, isprovided with a notch adapted to receive the opposite end 8l of theinterlock member. The flange portion 5la is provided with a cut-awayportion 82 which moves under `the end 11 of the interlock when the gradeselector is turned to reach the olf or non-grinding position; thisopening being sufficiently wide to permit oscillation of the hand wheelunder the action of the shock-absorbing functioning of the spring 10. Insuch position the interlock member is turned on its pivot by means ofspring 18 and the end 8l is caused to engage within the notch 80,thereby locking the handle I8 and preventing its movement toward onposition while the gradeselector remains in non-'grinding position. Uponrotation of the hand wheel to any one of the predetermined grindingpositions, the surface of 51a engages the end 11, causing the withdrawalof the member 8| from the notch 80, after which the control handle I8can be turned to 'the on" position to start the operation of the mill,i. e. vto start the motor and to open the gate for the admission ofcoffee to the mili. As shown the spring18 is coiled about the pin 16with one end bent about a pin 83 and the other end extended againstaflxed lug or abutment 8|, tov urge the end portion 11 at all timestoward the hand wheel.

Means are provided for latching the hand wheel in any of itspredetermined grinding positions. This vmeans comprises a plurality ofnotches 85 formed between 'ratchet teeth on the interior of the flangeportion 51a of the hand wheel. A latch member 86 is mounted upon a pivotpin 81 which 'is carried by the frame 53. A lsuitable spring 88urges theend portion 8 9 of the latch upwardlyinto the path of the teeth 85, andso into iatching position. These teeth are formed of such contour thatthe hand wheel can be turned in one direction, clockwise as viewed inFig.A 3, without interference from the latching member. However, thelatch, which engages successively in each of the' several notches andagainst the several teeth, will hold the hand wheel in any one of thesepredetermined positionsagainst -movement in the opposite direction; i.e., toward the coarser andnon-grnding positions.

Preferably the notches are so positioned as toand very fine. As shownthe `spring 88 is coiled l about the pivot pin iiI` with one end hookedabout a pin 88a carriedby'thelatch 86 and the other end abuts againstthe adjacentv portion of 53 and; the tension is such as to urge thelatch toward the notches between the teeth 85. i l

` Release means is provided `for the latching mechanism which is`interrelated with the control handle I8 for controlling the operation ofthemill, this interlocking` means providing for the release of thevlatching mechanism only when the control handle I8 is moved into suchposition as to stop the operation o! themill. This means includes the`disk 19, rotated with -handle I8, which is provided with a camsurface 90shown in dotted lines in Fig.- 3 which cooperates with a cam follower9I` suitably mounted within frame 53. Spring 92 retains member 9i inengagement with the cam surface at all times. The member 9| is providedwith anr outwardly extending finger 93, extending through a slot 94formed in the frame member 53, which is adapted toerigage a tongue 95formed upon the endof the latch arm In the position shown in Fig. 3, thegrade selecting means has been adjusted to a grinding. position,` andthe latch 86 retains the parts in such predetermined adjusted position,the control handle I8' being indicated in dotted lines for the onposition. In this position the cam follower 9| has moved to its upperlimit of travel andthe finger 93 does not depress the tongue 95, the end89 of the latching member therefore remaining in the latching position.,At the end of the .grinding operation, the handle I8 is moved to the offposition indicated in dotted lines in Fig. 4 (stopping the grindingoperation), where the cam frollower 9| is cammed downwardly, the iinger93- depressing tongue 55, to thereupon causethe disengagement oi the end89 ofthe latching member `from the notches 85, allowing the hand wheelto` be retur-nedtoits extreme end. or non-grinding position by means ofspring 10, which also absorbs the shock of return when ther hand wheelis released, as described above.

A reset mechanism comprising a pin 98 mounted within the frame 53 andspring pressed'. outwardly, provides for withdrawal of ythe latch 86when it is desired to momentarily release the latch from latchingengagement, as Vfor the resetting of the grade selector to a coarserposition. As will be obvious, no reset mechanism is required when thehand wheel is moved from a coarser to a finer position as the latchingmeans e does not prevent such movement.

From the above it will be clear that the interlock member 15 and itsassociated parts prevent starting of the mill until the grade selectormeans has been adjusted to a predetermined one of 'the 'grindingpositions. When so adjusted thescontrol handle can be moved to onposition and the mill placed in operation. the grade selector mechanismbeing retained in the selected position. At the end of the grindingoperation the control handle is turned to the oiI position, opening themotor switch and closing the gate, and simultaneously releasing thelatching mechanism to permit the grade selectorto be returned to itsnon-grinding `position under the inuenceof spring 1U, inwhich ingmechanism;

position the interlock 15 again becomes effective as above described. ye

In order to restore the action of the latching mechanism 86 when themill'hasubeen stopped, so that the grade selector will be retained inany adjusted position prior tothe opening movement oi the handle I8,means are provided for disabling vor withdrawing the action of thereleasing nger 93 when the grade selectory has been returned 1 tonon-.grinding position. To accomplish this re cam member IM carried uponthe inner face of hand. wheely Slis adapted to engage the end portionIDZof the latch BB3-when the hand wheely has been returned substantiallyto its end or nongrindinggposition.v `This engagement, as shown in Fig.6, produces a lateral swinging of the'latch member on its pivotl andwithdraws' the tongue 85' from the path ci thel finger allowing thespring 88 to return the latch into latching relationship with thenotches which are of sufiicient width to providev for vsuch engagement.Thus the release means, 9| etc., is disabled. and the latch is thereuponrestored to latching posi` tion under the action of its spring 88 whenthe grade selector is moved back to its non-grind position. Under thissetting the latch assumes the described lateral. position to beeffective to retain the hand wheel in any predetermined grindingposition irrespective of therelease means 81|, etc. which is thendisabled, while the handle isalso locked against turning by the latch'I5 and the grinding mechanism is` locked until the gra-de selector isthereafter moved to one of the grinding settings. When another grindingoperation is to be performed, the operator Will-move the hand wheel tothe desired grinding position which rocks ment thereof. As the handwheel remains in any set position, he will normally set thegradeselector and then the `handle I8 to start they mill, thus avoidingthe necessity for utilizing `two hands in theoperation of the mill.`

It is believed that the operation of the device will be clearly apparentfrom the above. Coffee is placed in the hopper I3 from a suitablecontainer, the gate I5k being closed to retain the coffee in the hopper.If desired, the same container may then be positioned below thedischarge outlet 41 to receive the ground coiee. The customers wisheshaving beenyascertained, the hand wheel is adjusted to the desiredgrinding position, and is retained there by the latch- If the.adjustment must be changed, the reset pin 98 may be operated to returnthe hand wheel toward its coarser positions.

The grade selector mechanism having beenL l Yelongated slotin the linkprevents interference of the one operating rod with the other,`providing y mechanism of the mill which discharges a homogeneous groundmaterial of predetermined fineness yinto the'container.

Attheend of the grindingoperation the handle I8 is turned to the offposition, resulting in the unlatching of the gradev selector whichthereupon is returned Ato its non-grinding position.

In such nongrinding position the interlock becomes effectivey to preventa subsequent operation of the control handle i8 until the grade selectormechanism has been vadjusted toapredeterrnined grinding' position,

Figs. 'l and 8 show an arrangement adapted for a mill having asngledriving motor, two separate hoppers, and two separate grinding means.

Such amill, sometimes known as a double ended mill,m ay have the samegrinding-means at each end, or mayf have differentrneans providing. forgrinding v to different grades ofl neness.r The presentinventionprovides for the controlled operation of `a double ended millin a manner similar .to'lthat described abovefor the single ended pairof overhanging shafts |22.

min. I i, v

I1`le rrlo 'tor` |20` i'sarrangedy substantially centrally of the casing|2 and is provided with a Grinding means .|23 of theconstructionldescribed above, are suit- `ablyjmounted and operated by`the respective shaftsin the-manner described above.

` Separate hoppers |24 are associated with theA respective grindingmeans, admission of the coffee to the hopper'sand the grinding meansbeing; controlled respectively by the gates I5. mounteduponshafts whichare actuated by con- 351trol handles I8.

The gates are Grade selecting means are positioned at each 4Vendofthefmachine, each of which may be con- -structedin exactly' the samemanner as described in detail above for the single-ended mill. Thedetailed construction of the interlocking mecha- "nism is preferably aduplicate oi that described' above-.for` the single-endedniill, andfurther 'description'is therefore unnecessary. v

`(Means are provided forcontrolling the actua- .t'ion-ofgthemotor vfromeither end ofthe mill.

For thislpurpose'theshafts I6 are provided with I crank arms 22' towhich are connected operating Prods` |32, each rod being provided with alink same controlled interlocking of the grade'selector i mechanism witheach control handle as with a.

75 single ended construction. j Before the", control |33 having'anelongated slot|34 formed therein.

The motor ,switch |35 is preferably positioned betweenthe rods |32 andspring means |36 tends to yieldingly .urge the switch toward theoffposition.

The switch is provided with an operating memberf|3`| which carries across bar |38 having sliding" engagement in both slots |34. vTheconstruction is such that when both control handles |8 are in theoffposition, as illustrated for instance by the left hand end; of the millin Fig. 7, links |33 Yare'drawn upwardly and the spring |36 causestheoperation of the switch arm |31 However, upon the operation lof eitheror both control handles to on position,v illustrated in the right handend of the mill of Fig. l, link |33 engages the rod |38'to cause'actoofff position.

tuation of the switch to the on positionfv The forfthe actuation of themotor'swtch to on positionwhen either operating handle is moved to onposition. l v

i s will be clearly evident fromthe foregoing description, thisarrangementI providesfor the 'ing' operation, the control lever ismovedto the .off position, Which `releases the grade selector mechanism whichthereupon is returned to the oil. :or non-grinding position by itsresilient means. Movementof the control handle at one .end of the millto the oi -position also effects the closing 'of the associated gate,and the stopping of the motor provided the other end of the mill is notinr operation. In case the other end of the mill is in operation, I'themotor will not be stopped'until both control handles'are turned to theoff position, but a subsequent operation of that end of the mill and theopening of its' gate will be prevented untilafter the grade selectormechanism at that end h as been readjusted to a desired grindingposition.v

While the forms of apparatus herein described constituteA preferredembodiments of the invention, it is to be understood that the 'inventionis not limited to these precise forms of apparatus, and thatchanges maybe made therein Without departing from'the scope of the invention whichis defined in the appended claims.

What is claimed is:

1. A coffee mill of the character described comprising ahousing, amotor, grinding means drivenby said motor and located within saidhousing,

'grade selector means for said grinding means adjustable fromyanon-grindingposition to a "plurality of grindingpositions', resilientmeans effective to move said grade selector means'to non-grindingposition, releasable means inaccessible within said mill for retainingsaidl grade selector. means in any selected grinding position againstreturnmovement, and reset means accessible from outsidesaid casing forreleasing said retaining means to provideV for the readjustrnentof saidgrade selector means.

v, v2. 'A coffee mill ofthe character described corn- Vprising ra motor,grinding means driven thereby,

grade selector means for said grinding means adjustablefrom anon-grinding position to a plurality of grinding positions, meanstending to move said grade selector'means to said nongrinding position,releasable means for retaining saidfgrade selector means in anypredeteryminedgrinding position, means forv controlling )the grinding ofcoffee, means operable upon the actuation vof said controlling means tostop the grindingof coffee for releasing said retaining means to allowsaid grade selector means to return to's'aid non-grinding position,I andmeans effective upon the return of said grade selector means to saidnon-grinding lpositionffor disabling thel action of said releasingmeans.'

31 A coffee millof the character described comprising a motor, a motorswitch having an operating member, vgrinding means 1 driven by saidmotor, grade selector means for said grinding means adjustable from anon-grinding position f to anyone of a plurality of grinding positions,

means tending to move'said grade selector to non-grinding position, saidmeans comprising a coiled spring under compression, and relativelymovable means connected tothe opposite ends of saidspring arranged tooverrun after the grade selector means is moved to off position wherebythe said spring acts to absorb the en- V ergy of movement, releasablemeans for retaining said` grade selector means in `any selected 3' lgrinding'position and means operated by the motorswitch operating memberfor releasing said `retaining means,'..whereby the grade'- selectorvmeans will be returned tooff action of said spring; i ,i l .l

4. A coffeemill ofthe `character described .com1 prisinga'motongrindin'g means, grade 'selector' position under the means forlsaid 'grinding meansadjustable frOm anon-grinding position toapluralityof grind- A ing positions, a motor sivitcli` and .a' handle for gradeselector means, a stop pawl positioned adjacent said handle with one end:cooperatively engaged with the said grade selector means, andvtheotherend adapted to be moved into stopt-y.y ping engagement with astop memberupon said handle, means for urging said pawl into stop- 1pingengagement `with said stopmember, and

means carried by vsaid grade 'selector effective, i upon said pawlwithin a predetermined portion i of therange of -movement of :said gradeselector `member to move said pawl out of' locking `engagementwitht'hesaid motor switch handle, said means being positioned to movesaid' pawl outy of locking engagement after'the grade selector means ismovedfrom the oii' position tothe first grinding position. n n

5. Acoiee mill of thecharacter described comprising motive means, aplurality of hoppers, a

pluralityk of grinding 'means vdriven by' said motive means andassociated respectively withjsaid plurality of `hoppers, gate means. forcontrolling admission of coffee from each' hopper into `its f associatedgrinding means, grade selectormeans -and-means preventing a subsequentopening of a closed gate means until after the adjustment of the gradeselector means associated therewith to f a grinding position. i,

6. A coffee mill of the character described comi prising motive means,`a plurality of hoppers, a

plurality .of grinding 'means drivenl by said motiverneansv and'.associated respectively with saidv plurality of hoppers, gate means forvcontrolling admission` of coffee` from eachA hopper .into itsassociated grinding means, grade selector means for each grindingmeansadiustable from a noni grinding position to, aplurality ci grindinglposi-` tions, means tending to move each grade selector means to itsnon-grinding position, releasable means for locking each lsaid, gradeselector means in any of its selected grlndingpositions, means effectiverupon the closing of any'of saidgate i means for releasing theassociatedlocking rneansA to allow the grade selector means :associatedtherewith to return to its non-grinding position, means preventing asubsequent opening of a closed gate means until after the adjustmentjof'the' grade selector meansassociated therewith. to a grinding position,and means effective when any o f said gate means is opened for startingsaid motive means and for stopping said motive means when none of saidgate means is in open position.

7. In a coil'eel mill provided with a motor,

grinding means operated thereby," gradefselector means forisaid grindingmeans adjustable fromy a non-grinding position to a plurality ofgrinding-positions, resilient means'` effective to' movev` said gradeselectory meansv to non-grindingposil, tion, la motor switch, agate'for` controlling the admission of coffee to said grinding means,and'` a commen-control member for said Vgate and said switch providingfor opening movementof said gate concomitantly with closing movement ofoperating said switch positioned adjacent said: theswitch;v meanseiectivefor.controlling'the' for retaining thev grade selector meansinany selected lgrinding position against returnjmove@ ment prior tooperation of said control member to "effect the closingof said gate. and'theop'lening ofA said switch-member, andV lmeans, operable` uponclosing said gate for withdrawing saidf latch' means from latchingposition 'to provide for return of said grade selector "to 'non-grindingposition. f

8. A conelnuu of the character' 'described com j prising a motor,grindingmeans, gradeselector means for said grinding meansadjustablejrom a non-grinding position toa plurality of grindingpositions, means tendingto movev said grade seing means forpreventing'movement of said grade selector means from a. grindingposition toward a i coarser grinding position whilev permitting movementvthereof toward a finer grindingtposition. v

comprising a motor,v grinding means, vgradeseoperationgoi'- said millcomprising latcl'iing",meansl 15 lector means to non-grinding position,and retainf30 l `9.r A coffee v'mm2 f the character described .35

lector means for said grindlng'means adjustable from anon-grinding'position` toa` pluralityy of grinding positions, meanstending to move, said grade 'selector' means to non-grinding position,retaining means for preventing movementof said grade'selectonmeans froma grinding positiontowarda lcoarser grinding position while permittingmovement thereof toward a liner-grinding position, and means underthecontrol of theoperator for releasingv saidretaining means-5toprovideior thefreturnof` said grade selector means toward a coarsergrinding position and toward said non-grinding position;` f p10. A'coffee mill of` the character described lcomprising amotor', grindingmeans,` a gate for controlling the introduction of coiee to saidgrinding means, 'gradeselector means for ,said

grinding means adjustable from a non-,grinding position to a pluralityof grinding positions, means tending to move saidgrade selector means.to 'l non-grinding position, retaining meansfor pre.- venting movementofsaid grade selector means from a grindingposition ltowarda position`of coarser grindjwhile providing for movement thereof toward a positionof-,ner grind, and means controlled in response to' movement of saidgate ltoward closed position for releasing .said

retainingmeans and providing for the` returnf ofv said.` grade selectormeans to non-grinding position.. ,4 l

11. A mill of the character described comprising a motor, amotorjswitch, grinding meansoperated by" said motor, grade selectormeans for said grinding means adjustable from a non-grinding positionvto `a plurality of grindingpositions, resilient `means effective tomove saidy grade selector meansto non-grinding position, a gate forcontrolling admission of material to be ground tosaid grinding means, acontrol means for saidk gate and said motor switch operable from an oil!position to an on position vto open said gate and energize said motor,and latching means operative when said control means is' in oil positionand during the subsequent movement thereof to on position for yretaining vsaid grade selector means in any selected grinding positionagainst return movement.

12. A mill otlthe character described comprising a motor, Y grindingmeans, grade selector means for said grinding means adjustable from anon-grinding position to a plurality of grinding positions, resilientmeans eective to move said grade selector means to non-'grindingposition, a gate for `controlling admission of material to be ground tosaid grinding means, .latching means' operative when said gate is inclosed position and during the subsequent movement of the gate to openposition for retaining said grade selector means 'in any 'selectedgrinding position' against return movement, and means operable upon theclosing of said gate` for effecting withdrawal ofsaid latching means toprovide for return ofsaid grade' selector means to non-grindingposition. v

13. Inl almill of the character described provided withjamotor, a motorswitch, grinding means operated by said motor, grade selector means forsaid grindingmeans adjustable from anon-grinding position to a pluralityof grinding positions, resilient means eiective toV move said gradeselector means to non-grinding position,

and latching means operable when said switch is in circuit openingposition andduring the vsubsequentclosing thereof for retaining saidgrade selector means in any selected grinding position' against returnmovement.

14. In `a mill 'of the character described provided `with va motor, amotor switch, grinding means, gradev selector means i'or said grindingmeans adjustable from a non-grinding position to a plurality o1*grinding positions, resilient means eilective to move said gradeselector means to non-grinding position, latching means operable whensaid switch is in circuit opening position `and Aduring the subsequentclosing thereof for retaining said gradeselector means in any selectedgrinding position against return movement, and means operable upon theopening of said switch for effecting withdrawal 'of said latching meansto provide for return of said grade selector means to non-grindingposition.

15. A mill of the character described provided with a motonxsw'itchmeans therefor, grinding means, grade selector means for said` grindingmeans adjustable from a non-grinding position to a plurality -ofgrinding. positions, resilient means eiective to move said gradeselector means to non-grinding position, latcliing means for r'etainingsaid grade selector means in any selected grinding -position againstreturn movement, means operable uponoperation of said switch to openrcircuit position for effecting withdrawal of said latching means toprovide for return of said grade selector -ineans to non-grindingposition, and means f; ,operable in the non-grinding position of. saidgrade selector for restoring vthe action of said latching means inpreparation for a subsequent cycle of operation of the mill.

16.l A .mill of the character described provided with a motor, grindingmeans, grade selector means for said grinding means adjustable vfrom anon-grinding position to a plurality of grinding positions, resilientmeans effective to move said grade selector means to non-grindingposition, a gate for controlling admission of material to be ground tosaid grinding means, latching means for retaining said grade selectormeans in any selected grinding position against return movement, meansvoperable upon closing of said gate for effecting withdrawal ot saidiatching means to provide for return of said'grade selector means tonon-grindingrposition, and means operable in the non-grinding positionof said grade selector for restoring the action of said latching meansin preparation for a subsequent cycle of operation of the mill.

'17. A1 coffee mill of the character described comprising a motor,grinding means driven thereby, grade selector means for said grindingmeans adjustable from a non-grinding position to a plurality of grindingpositions, means tending to move said grade` selector means to saidnongrinding position, releasable means for retaining said grade selectormeans in any predetermined grinding position, means i'or controllingthegrinding of coffee, means operable upon the actuation of saidcontrolling means to stop the grinding of' coffee for releasing saidretaining means to allow said grade selector means to re- ,turn to saidnon-grinding position, and means effective' upon the return of saidgrade selector means to said-non-grinding position'for disabling theaction of said releasing means.

18. A coifee mill of the character described comprising motive means, aplurality oi hoppers, a plurality of grinding means driven by saidmotive means and associated respectively with said plurality of hoppers,gate means ior controlling admission of coffee from each hopper into itsassociated grinding means, grade selectormeans for each grinding meansadjustable from a nongrinding position to a plurality of grindingpositions, means tending to move each grade selector means to itsnon-grinding position, reieasable means for locking each said gradeselector means in anyof its selected grinding positions, and meanseffective upon the closing of any of said gate means for releasing' theassociated locking means to allow the 'grade selector means associatedtherewith to return to its non-grinding position.

i9. A coffee mill of the character described comprising motive means, aplurality of hoppers, a plurality` of grinding means driven by saidmotive means and associated respectively with said pluralityof'hoppers,gate means for controlling admission of coffee from each hopper into itsassociated grinding means, grade selector means for each grinding meansadjustable from a. non-grinding position fto a plurality of grindingpositions, means tending to move each grade selector means ,to itsnon-grinding position, releasable means for locking each said gradeselector means in any of its selected grinding positions, means`effective upon the closing of any of said gate mea-nsfor'releasing theassociated locking means to allow the grade selector means associatedtherewith to return to its non-grinding position, and control means forcausing operation of said motive means to drive said grinding means whenFany of said gate means is in open position and for stopping said motivemeans when none of said gate means is in open position.

DAVID A. MEEKER.

